PEP 245

[Clark C. Evans]

> It is clear to me that either I am the only one who things 
> that interfaces, at least in the proposed form, are next to 
> useless in Python, or those who agree with me do not read the 
> news group, or simply don't care enough to reply.

Some mechanism is needed to identify an object as
an implementer of a particular protocol, searching
for the existance of "getitem" and the like seems
like very poor practice.  

> Indeed, interfaces in a loosely typed language that 
> supports introspection -- that's a real joke!

What is important isn't the function names,
but rather the "intent" of the programmer
who asserts that his/her class complies with
a given set of expectations.  There currently
isn't a standard way to express this in Python.
I think PEP 245 is a good approach.

I think most people agree that Python has
a "hole" here that needs to be plugged.  If
you don't like the current proposal, perhaps
you should suggest an alternative which 
provides the required differentiation?

Either that or make a convincing argument
why searching for function names is indeed
acceptable.  I think it breaks down quickly.
For instance __iter__ has to return self
in the iterator proposal to know that 
a class is an iterator (having the method
"next()" is not sufficient).  This kind
of ad-hock interface negotiotation kinda
hurts interoperability, no?

Just thinking...

Clark